If that means finding elements while working it the Family Editor, where the GenericForm class (Extrusion, Sweep, Blend, etc) have a Subcategory property, then yes we can do that.

Run this macro after selecting an element (such as an extrusion in with the Frame/Mullion subcategory in a Window family) and all the other Frame/Mullion elements will get selected too.

public void SelectBySubCat()
{
  var uidoc = this.ActiveUIDocument;
  var doc = uidoc.Document;
  var forms = uidoc.Selection.GetElementIds()
    .Select(q => doc.GetElement(q))
    .Where(q => q is GenericForm)
    .Cast<GenericForm>();
  var sameSc = new List<ElementId>();
  foreach (var form in forms)
  {
    sameSc.AddRange(
      new FilteredElementCollector(doc)
      .OfClass(typeof(GenericForm))
      .Cast<GenericForm>()
      .Where(q => q.Subcategory.Id == form.Subcategory.Id)
      .Select(q => q.Id)); 
  }
  uidoc.Selection.SetElementIds(sameSc);
}

The “RevitLinkGraphicsSettings” class was introduced in the 2024 API and allowed us to set the LinkedViewId.

Revit 2025 added many more methods

So now you can use the API to get and set everything here on the “Basics” tab.

Here is some code to set the linked view, color fill, and discipline

var linkInstances = new FilteredElementCollector(doc)
      .OfClass(typeof(RevitLinkInstance))
      .Cast<RevitLinkInstance>();

        using (var tr = new Transaction(doc, "d"))
        {
          tr.Start();
            foreach (var linkInstance in linkInstances)
            {
              var view = new FilteredElementCollector(linkInstance.GetLinkDocument())
                .OfClass(typeof(ViewPlan))
                .FirstOrDefault(q => q.Name == "L1NoAnnotations");
                var gs = new RevitLinkGraphicsSettings
                {
                     LinkVisibilityType = LinkVisibility.Custom,
                     LinkedViewId = view.Id,
                     ColorFill = LinkVisibility.ByLinkView
                };
                gs.SetDiscipline(LinkVisibility.Custom, ViewDiscipline.Mechanical);
                doc.ActiveView.SetLinkOverrides(linkInstance.Id, gs);
            }
            tr.Commit();
        } 

But that looks like as far as we can go. If your goal is to turn off this checkbox, we still need to wait for Autodesk to expose that functionality to the API

If so, send your questions, suggestions, and wishes for things that might be possible to achieve with the Revit API & a handful will be selected, implemented, and shared here in future posts.

You can find some past wishes that were granted at https://boostyourbim.wordpress.com/category/api-wish/rtc/

And let me know you are here in San Diego and want to say hi!

public void ShowWallStructureOnly()
{
    var doc = this.ActiveUIDocument.Document;
    View3D view;
    using (Transaction t = new Transaction(doc, "create wall structure view"))
    {
        t.Start();
        view = View3D.CreateIsometric(doc, new FilteredElementCollector(doc)
                                        .OfClass(typeof(ViewFamilyType))
                                        .Cast<ViewFamilyType>()
                                        .First(q => q.ViewFamily == ViewFamily.ThreeDimensional).Id);
        if (doc.ActiveView is View3D)
        {
            view.SetOrientation(((View3D)doc.ActiveView).GetOrientation());
        }
        view.PartsVisibility = PartsVisibility.ShowPartsOnly;
        PartUtils.CreateParts(doc, new FilteredElementCollector(doc, view.Id).OfClass(typeof(Wall))
                              .Where(q => PartUtils.IsValidForCreateParts(doc, new LinkElementId(q.Id)) && !PartUtils.HasAssociatedParts(doc, q.Id))
                              .Select(q => q.Id).ToList());
        doc.Regenerate();
        var toHide = new List<ElementId>();
        foreach (var part in new FilteredElementCollector(doc, view.Id).OfClass(typeof(Part)))
        {
            // I expected DPART_ORIGINAL_TYPE would store the element id of the wall type
            // but it stores the wall type's name as a string
            var typeName = part.get_Parameter(BuiltInParameter.DPART_ORIGINAL_TYPE).AsString();
            
            var wallType = new FilteredElementCollector(doc)
                .OfClass(typeof(WallType))
                .Cast<WallType>()
                .First(q => q.Name == typeName);
            var layers = wallType.GetCompoundStructure().GetLayers();
            var parameter = part.get_Parameter(BuiltInParameter.DPART_LAYER_INDEX);
            if (parameter == null)
            {
                continue;
            }
            
            // I expected DPART_LAYER_INDEX would store the index as an integer
            // but it stores it as as string
            var layerInt = int.Parse(parameter.AsString());
            var layer = layers[layerInt - 1];
            if (layer.Function != MaterialFunctionAssignment.Structure)
            {
                toHide.Add(part.Id);
            }
        }
        if (toHide.Any())
           view.HideElements(toHide);
        t.Commit();
    }
    this.ActiveUIDocument.ActiveView = view;
}

An enhancement to this code could be to check the function of each wall type layer once, not once per wall.

And I moved some code around so that it would recursively handle all nested subfamilies

       private void MergeFamilies(Document doc, ElementId categoryId, List<string> namesOfSubcategoriesToMerge, string newCategoryName)
        {
            List<Family> families = new FilteredElementCollector(doc)
                .OfClass(typeof(Family))
                .Cast<Family>()
                .Where(q => 
                q.FamilyCategoryId == categoryId &&
                q.Name != string.Empty)
                .ToList();
            foreach (var family in families)
            {
                MergeFamilies(family, categoryId, namesOfSubcategoriesToMerge, newCategoryName);
            }
        }
        private void MergeFamilies(Family f, ElementId categoryId, List<string> namesOfSubcategoriesToMerge, string newCategoryName)
        {
            var document = f.Document;
            var famDoc = document.EditFamily(f);
            // update any subfamilies before this family
            MergeFamilies(famDoc, categoryId, namesOfSubcategoriesToMerge, newCategoryName);

And here is the source code and updated installer. Enjoy!

Yes – DONE!

Code here

We can do all of that, with a limitation that the API does not have the “Apply Area Rules” option that exists in the Revit UI. So whether we copy the existing boundary lines into the new Area Plan, or create new ones, they will not follow the area rules. But Cillian, who is working in Finland, does not use those rules anyway, so here is the new tool that is hopefully useful to Cillian and some other people too!

• Area
• Area Tag
• Wall
• Floor

https://bitbucket.org/BoostYourBIM/boostyourbimterrifictools/src/master/BoostYourBIMTerrificTools/RoomAreaBoundaries/